Dexter works
there as a blood-splatter expert, so when he isn't out killing someone
(or visiting Rita), he spends a lot of time at the police station, interacting
with co-workers Angel, Masuka, LaGuerta, Doakes - and his sister Debra
(who also works there, as a cop).

Often we see
only the interior, and sometimes we see the outside of the station.

One example
of the exterior is in Episode 5 (of season one), "Love American Style",
at around 10:17.

Q.
What is it actually in real life?

A. It's a little
complicated.

In the first
season, the police headquarters was just a false front that they built
against the blank side of a large sound stage at Sunset-Gower studios.
That's why, during those exterior scenes, you usually never see anything
beyond the front of the building and the "parking lot".

The interior
of the police station, of course, was just a studio set, built inside Sound
Stage 16. (Other permanent sets for "Dexter" include the
interior of Dexter's apartment and the interior of Rita's home).

You still see this parking lot quite often on the show.

In the second
season, the producers got more creative and started branching out.

So, in real
life, the Miami Metro Police Headquarters is actually an amalgam of
at least five different locations.

Q.
Where can I find it in real life?

A. Sunset-Gower
Studios can be found (appropriately enough) at the southeast corner
of Sunset Boulevard & Gower Street. The address is 1438 N. Gower
Street, in Hollywood.

"Dexter"
is filmed inside Sound Stage 16, which is near the southeast
corner of the studio, as seen on the map below.

The police station
exterior was created in the parking lot on the east side of Stage 15.

When you see
scenes set in the police parking lot, including those lunch scenes
with a catering truck, most of those were in the parking lot just outside
that same sound stage, in the southeast corner of the studio (Fountain
Ave & Gordon St.)

But you can't
get inside the studio unless you have business there (or are attending
a taping).

A. While looking
at the exterior scenes of the police station, trying to figure out where
it was, I was struck by how limited the views were, and how similar
the shots were, time after time. I suspected that it might just be a false
front at the studio lot. Eventually, I was able to verify this with someone
who worked on the show.

To pinpoint
the exact spot at the studio, I took a look at Episode 5, "Love American
Style", where Dexter talks to a cop in the police parking lot. As
the camera follows him, and turns to the east, you can briefly see the
buildings across the street, and I was able to match them via Live Local
aerial photos to the buildings on Gordon Street, just north of Fountain
Avenue. Which meant that they had set up shop in the small Fountain parking
lot, inside the studio walls, at the northwest corner of Gordon & Fountain
(on the east side of Stages 15 & 16).